You need to run two processes in the background, one of them is websocket: RAILS_ENV=production ruby script/websocket_server.rb &

The second process is a resque worker. It is responsible for background tasks. You can start it with: RAILS_ENV=production QUEUE=receive,mail,receive_local,socket_webfinger,http_service,http,receive_salmon bundle exec rake resque:work

Feel free to ask questions, I will try to extend the howto.
…

apparmor and mod_passenger

It is possible to protect passenger with apparmor. You need to create the following wrapper: